On Sat, May 19, 2018 at 04:24:40PM +0800, Wei Hu (Xavier) wrote: > > > On 2018/5/17 23:00, Jason Gunthorpe wrote: > > On Thu, May 17, 2018 at 04:02:49PM +0800, Wei Hu (Xavier) wrote: > >> This patch Implements the IB core disassociate_ucontext API. > >> > >> Signed-off-by: Wei Hu (Xavier) <xavier.huwei@xxxxxxxxxx> > >> drivers/infiniband/hw/hns/hns_roce_main.c | 36 +++++++++++++++++++++++++++++++ > >> 1 file changed, 36 insertions(+) > >> > >> diff --git a/drivers/infiniband/hw/hns/hns_roce_main.c b/drivers/infiniband/hw/hns/hns_roce_main.c > >> index 96fb6a9..7fafe9d 100644 > >> +++ b/drivers/infiniband/hw/hns/hns_roce_main.c > >> @@ -33,6 +33,9 @@ > >> #include <linux/acpi.h> > >> #include <linux/of_platform.h> > >> #include <linux/module.h> > >> +#include <linux/sched.h> > >> +#include <linux/sched/mm.h> > >> +#include <linux/sched/task.h> > >> #include <rdma/ib_addr.h> > >> #include <rdma/ib_smi.h> > >> #include <rdma/ib_user_verbs.h> > >> @@ -422,6 +425,38 @@ static int hns_roce_port_immutable(struct ib_device *ib_dev, u8 port_num, > >> return 0; > >> } > >> > >> +static void hns_roce_disassociate_ucontext(struct ib_ucontext *ibcontext) > >> +{ > >> + struct task_struct *process; > >> + struct mm_struct *mm; > >> + > >> + process = get_pid_task(ibcontext->tgid, PIDTYPE_PID); > >> + if (!process) > >> + return; > >> + > >> + mm = get_task_mm(process); > >> + if (!mm) { > >> + pr_info("no mm, disassociate ucontext is pending task termination\n"); > >> + while (1) { > >> + put_task_struct(process); > >> + usleep_range(1000, 2000); > >> + process = get_pid_task(ibcontext->tgid, PIDTYPE_PID); > >> + if (!process || process->state == TASK_DEAD) { > >> + pr_info("disassociate ucontext done, task was terminated\n"); > >> + /* if task was dead, need to release the task > >> + * struct. > >> + */ > >> + if (process) > >> + put_task_struct(process); > >> + return; > >> + } > >> + } > >> + } > > I don't want to see this boilerplate code copied into every > > driver. Hoist it into the core code, have the disassociate driver callback > > accept a mm_struct parameter, and refactor the other drivers using this. > > When the userspace RDMA application process is suspended for some reason > without executing ibv_close_device function, > There will be calltrace as follows when rmmod roce kernel driver ko in > the current version. > It looks like a common problem to every driver and the code segment > above is suitable for every driver. > Pardon me for asking, but if you have any plan to do this? My plan is to ask you to do it :) Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html